package com.yitao.cms.utils;

import java.io.*;

/**
 * @Author: wwl
 * @Date: 2019/5/7 14:54
 * @Description:
 */
public class ImageTypeUtils {
    public static final String TYPE_JPG = ".jpg";
    public static final String TYPE_GIF = ".gif";
    public static final String TYPE_PNG = ".png";
    public static final String TYPE_BMP = ".bmp";
    public static final String TYPE_WEBP = ".webp";
    public static final String TYPE_TIF = ".tif";
    //public static final String TYPE_TIFF = ".tiff";
    public static final String TYPE_UNKNOWN = "unknown";


   /* public static void main(String[] args) throws FileNotFoundException {
        File pdfFile = new File("C:\\Users\\Public\\Pictures\\Sample Pictures\\F35245_113_P2.jpg");

        //test code
        System.out.println("图片格式1： " + getPicType(new FileInputStream(pdfFile)));

    }*/
    /**
     * byte数组转换成16进制字符串
     * @param src
     * @return
     */
    public static String bytesToHexString(byte[] src){
        StringBuilder stringBuilder = new StringBuilder();
        if (src == null || src.length <= 0) {
            return null;
        }
        for (int i = 0; i < src.length; i++) {
            int v = src[i] & 0xFF;
            String hv = Integer.toHexString(v);
            if (hv.length() < 2) {
                stringBuilder.append(0);
            }
            stringBuilder.append(hv);
        }
        return stringBuilder.toString();
    }

    /**
     * 根据文件流判断图片类型
     * @param fis
     * @return jpg/png/gif/bmp
     */
    public static String getPicType(FileInputStream fis) {
        //读取文件的前几个字节来判断图片格式
        byte[] b = new byte[4];
        try {
            fis.read(b, 0, b.length);
            String type = bytesToHexString(b).toUpperCase();
            if (type.contains("FFD8FF")) {
                return TYPE_JPG;
            } else if (type.contains("89504E47")) {
                return TYPE_PNG;
            } else if (type.contains("47494638")) {
                return TYPE_GIF;
            } else if (type.contains("424D")) {
                return TYPE_BMP;
            }else if(type.contains("52494646")){
                return TYPE_WEBP;
            }else{
                return TYPE_UNKNOWN;
            }
        } catch (IOException e) {
            e.printStackTrace();
        }finally{
            if(fis != null){
                try {
                    fis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return null;
    }
    /**
     * 根据文件流判断图片类型
     * @param fis
     * @return jpg/png/gif/bmp
     */
    public static String getPicType2(InputStream fis) {
        //读取文件的前几个字节来判断图片格式
        byte[] b = new byte[4];
        try {
            fis.read(b, 0, b.length);
            String type = bytesToHexString(b).toUpperCase();
            if (type.contains("FFD8FF")) {
                return TYPE_JPG;
            } else if (type.contains("89504E47")) {
                return TYPE_PNG;
            } else if (type.contains("47494638")) {
                return TYPE_GIF;
            } else if (type.contains("424D")) {
                return TYPE_BMP;
            }else if(type.contains("52494646")){
                return TYPE_WEBP;
            }else{
                return TYPE_UNKNOWN;
            }
        } catch (IOException e) {
            e.printStackTrace();
        }finally{
            if(fis != null){
                try {
                    fis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return null;
    }

}
